I would like to ask if colour filters use to photograph – the filters we use to put in front of a lens in a camera- is a subtractive method?
Additive and subtractive methods refer to how colors are mixed, not the properties of a single stimulus (like a filter). Photographic filters work by absorbing light (some wavelengths more than others if they are colored). That is the simple physical process that gives a filter it’s color. If you were to stack two or more filters together, then you would use the principles of subtractive color mixing to predict the color of the combination. If instead you were to project spotlights through each of the filters individually and then superimpose the spotlights, you would use the principles of additive color mixing to predict the resulting color.
